There is no doubt that a more powerful round is better but Shot placement is still what is going to determine how fast the target goes down. If shot placement is the same the target will most likely go down faster if hit with the more powerful round. I know a cop that shot a BG 4 times with a .45, 185 HP rounds, didn't knok him down, the guy turned and walked across the street and fell. Still alive to this day. None of the rounds hit him in the head, neck, or backbone.